This invention relates to a cage position display apparatus for an elevator capable of altering a display character aspect.
FIG. 10 is a schematic arrangement diagram which shows by way of example a prior-art position display apparatus for an elevator system disclosed in Japanese Patent Application Publication No. 57391/1982 (U.S. Pat. NO. 3,995,719). Numeral 1 designates means provided in a machinery room-control device 10 for generating a binary signal expressive of a cage position. Memory means 2 disposed in a display device 11 receives the outputs from the binary signal generation means 1 through signal lines 4, and delivers positional character signals corresponding to a pertinent cage position. Display means 3 receives the positional character signals through internal wiring 5, and presents a character display.
Next, the operation of the prior-art apparatus will be explained on the basis of the above construction. When a cage passes through or stops at each floor within the hoistway of the elevator, the machinery room-control device 10 receives a position signal indicative of the floor from a predetermined position detection mechanism. The position signal is converted by the binary signal generation means 1 into a binary signal, which is sent to the memory means 2 of the display device 11 through the signal lines 4. The binary signal represents an address of the memory means 2 which stores in its contents corresponding cage positions in accordance with a predetermined arrangement. The display device 11 is then operated to read out from the memory means 2 and to send to the display means 3 through the internal wiring 5 the corresponding page position.
As understood from the above example of the operation, even in a case where the number of the signal lines 4 laid between the binary signal generation means 1 of the machine room control device 10 and the memory means 2 of the display device 11 and the number of the wiring leads 5 laid between the memory means 2 and the display means 3 are fixed, an expressing format for respective floors can be readily altered to a symbolism specific to a building by altering the content of the memory means 2 (for example, "1" indicative of the first floor can be altered to "G" indicative of the ground floor). Besides, the field wiring of the machine room control device 10 (usually located at the top part of the building) as well as the display device 11 can be simplified and can also be standardized.
The prior-art position display apparatus for the elevator system is constructed and operated as described above, and it is very effective in case of installing the position display device 11 in the cage only.
However, it is often necessary to display the cage position, not only in the cage, but also in the halls of the respective floors as illustrated in FIG. 11. Accordingly, in an elevator which stops at 32 floors by way of example, the memory means 2 storing a predetermined floor arrangement are disposed in the cage and all 32 elevator halls, totaling 33 units. When there is a need to change a display symbolism or floor arrangement, the contents of all these memory means 2 need to be altered. Specifically, the display symbols "L" corresponding to the first floor and "1" corresponding to the second floor provided in the memory contents of 33 units of the memory means 2 need to be changed and replaced by "1" and "L", respectively, when the second floor is now made the lobby. Clearly, every time there is a change, all the memory units are replaced since their memory contents are often set permanently according to a specific floor arrangement. This replacement task is very time-consuming and expensive since new units and additional labor are required. On the other hand, to eliminate such a drawback, it is considered to install a single memory means 2 in the machine room control device 10 and only the individual display means 3 in the cage and elevator halls of the respective floors and to place field wires connecting the memory means 2 to the display means 3 within the hoistway. However, by so doing, the number of field wires increases dramatically, lowering reliability due to exposure and poor maintainability. Particularly, when individual memory means 2 are disposed in the position display devices 11, there are only 5 field wires connecting between the binary signal generation means 1 of the machine room control device 10 and the memory means 2 and corresponding to a 5-bit representation of 32 decimal display symbols for 32 floors. When the single memory means 2 in disposed in the machine room control device 10, 14 field wires corresponding to a 14-bit representation of two 7-segment display units required for displaying up to 99 symbols are needed for the connection to the display means 3. If two 16-segment display units are employed for each display means 3 (and there are 33 display means for 32 elevator halls and a cage), there will be 33 parallel connections, each with 32 field wires coming out of the machine room control device 10. As the number of floors and elevator cages increases, the number of field wires maintained within the hoistway is prohibitively large.